VSRs

Some battery combiners (also called voltage controlled relay, or split charge relay) will disconnect a battery in case of a short but high amperage load. A battery combiner also fail to connect a large but discharged battery bank because the DC voltage immediately drops below the disengage value once the batteries are connected. 

The software of the Cyrix-ct 12/24 does more than simply connect and disconnect based on battery voltage and with a fixed time delay: it looks at the general trend (voltage increasing or decreasing), and reverses a previous action only if the trend has reversed during a certain period of time. The time delay depends on the voltage deviation from the trend.

Suitable for use with solar panels, wind power, and alternators. There are no moving parts, and the fully encapsulated electronics make it suitable for marine use.

• Bidirectional voltage sensitive relay - will engage if the accessory battery is being charged by other means
  
• Intelligent battery monitoring - the Cyrix looks at the general trend of voltage increasing or decreasing, and reverses this action only if the trend has reversed.
• Easy to install - no reason to cut into any factory wiring that may void the manufacturer's warranty on boats or vehicles.

Specifications:

12V: makes at 13.3V and breaks at 12.8V

24V: makes at 27.4V and breaks at 25.6V

Dimensions: 46 x 46 x 80 mm

Weight: 110g

N.B. Due to their highly variable voltage, this VSR is not suitable for use with 'smart' alternators.